The invention is based on a method for increasing the precision of paths in numerically controlled machine tools, and more particularly to a method of determining a parameter for auxiliary control in a position control loop of the numerically controlled path of a machine having i axes. One proposal for increasing path precision by superimposing auxiliary values is known from "Zeitschrift fur industrielle Fertigung" (Journal for Industrial Manufacturing), 1978, Pages 329 to 333. This reference describes a plurality of possibilities for influencing the guidance variable of the position control of a machine tool. In this prior art method of auxiliary control, the desired position signal is supplemented by adding suitably weighted control signals. The particular goal of the arrangements proposed in the Journal for Industrial Manufacturing, 1978, Pages 329-333 is to improve path precision while travelling through a corner. With respect to the superimposition of auxiliary values, the reference is limited to the possibility of auxiliary control of speed, i.e., superimposing an auxiliary signal that is proportional to the guidance speed. Auxiliary control of the accelerated guide speed, i.e., superimposing an auxiliary value in the form of an acceleration signal proportional to guidance acceleration or greater derivations of the guidance variable, is not provided. This reference does not give any information on how the auxiliary control parameters required for carrying out the auxiliary control for greater derivations of guidance variables can be obtained.
EP 0,184,036 also discloses a control method for NC machines that employs the auxiliary control method. Moreover, NC (numerically controlled) control units are available commercially, for example, from the FANUC and OSAI companies of Japan, which also use the auxiliary speed control method. The parameters required for auxiliary control in this case are exactly predetermined or they are set empirically for each machine.